Dental handpiece



R. E. GRAVES.

DENTAL HANDPIECE.

APPLICATION FILED JUNE 21, 1919.

nun 51135311? m ROBERT E. GRAVES, OF HOUSTON, TEXAS.

DENTAL HANDPIECE.

Specification of Letters Patent.

Patented An". 17, 1920.

Application filed June 21, 1919. Serial No. 305,829.

To all whom it may concern:

Be it known that I, Roenirr E. Gnavns, a citizen of the United States, residing at Houston, in the county of Harris and fitate of Texas, have invented certain new and useful Improvements in Dental llandpieces, of which the following is a speclfication.

This invention relates to new anduseful improvements in a dental hand piece.

()ne object of the invent on is to proyide a hand piece of the character described which has been specially designed to recelve the drill. and whereby said drill may be readily secured in or released from said hand piece.

Another object of the invention is to provide a dental hand piece of the character described which is simple in construction and composed of few parts, and whlch 1s consequently cheap in manufacture.

With the above and other olnects in view, the invention has particular relation to certain novel :t'eaturcs of construction, operation and arrangement of parts, an example of which given in this specification and illustrated in the accom 'ianying drawlngs, wherein Figure 1, is a longitudinal sectional view of the device. 7

Fig. 2 is a cross sectional view of Fig. 1, taken on the line 2-2.

Referring now more particularly to the drawings wherein like numerals of reference. designate similar parts in each of the figures, the .i'iumeral 1, refers to the tubular casing, one end of which is reduced, forming the neck 2 which is outwardly threaded to re ceive the usual connection Iiastened to the periphery of the casing by means of thesct screw 3, tl'iere is a flat spring l whose free end carries the inwardly extending pin 5, which projects through an aliined hole in. the Fastened to the head of this pin, there is a long llat spring 6, which operates over the head of the screw 3 as a fulcrum and whose free end has the thumb knob 7, and also carries the inwardly extending pin 8, which projects through an alined orifice in' the casing. Fitted within the casing, there is the tubular sleeve 9, having the orifice 10 therein, into which theinner end of the pin normally projects. The inner end of this sleeve also has the flattened side 11 opp0s ing the inner end of the pin 8. The out wardly projecting end of the sleeve 9 is reduced beyond the corresponding end of the casing 1, and has the internal annular shoulder 12, near its free end, and the free end of said sleeve has the bearing 13 through which the dental drill is fitted. The numeral 14 refers to the drive shaft which is fitted within the sleeve 9. The outer end of this shaft carries the dog 15, by means of which the shaft may be operatively connected with and driven from a suitable motor, through. the usual flexible COHHOCtlOJl common to dental apparatus, and the other end 16 of said shaft is reduced and tapered, and formed into a split chuck 17, provided to receive the drill. Threaded over the reduced. portion 16 of the shaft there a clamp nut 18 provided with the end notch 19. This nut is formed to conform to the tapering end of the shaft and when the drill is inserted into the chuck, and the nut screwed up tightly, said nut causes the chuck to clamp and hold the drill, and when the nut is partially unscrewed, the drill is released and may he removed. The reduced end of the sleeve 9 is formed with an into gral covering 20 of hard rubber "r guttapercha, and a set screw 21 is threaded through said covering and sleeve, and its inner end projects into the space 22, formed between the reduced end of the shaft 14:, and the sleeve 9, in front of the annular Sliollhlcl' 24:, of said shaft, The nut 18 being entirely :inclosed, it is out of the reach of the operator, so when, it is desired to turn said nut, either to screw the same up, for tightei'iing the chuck on the drill, or for-unscrewing the same to release the drill, the thumb knob? is depressed by a downward and backward pull thereon, and this will. operate through the spring 6, actiiig upon the head of the screw 3 as a fulcrum to lift the pin 5 out of the orifice 10, and the sleeve 9 may then be forced forwardly, relative to the casing 1, until the corresponding end thereof passes the pin 8 and said pin will then-drop into the recess 23 of the shaft 14- and lock said shaft against rotation. This forward movement of the sleeve 9 carries the inwardly projecting end of the screw 21 into the notch 19, of the clamp nut 18 and said sleeve may then be turned in either direction to screw up or unscrew said clamp nut and thereby tighten the chuck on the drill or release the same therefrom. \Vhen the thumb knob 7 is released, the spring 6 will withdraw the pin 8 from the recess 23 and clear the inner end of the sleeve 9, and

said sleeve may then be pulled back to its original position, and it will be. there held by the pin 5 which is again projected into the orifice 10 by the action of the spring a.

What I claim is: w

1.. A dental hand piece including a casing, a sleeve titted therein, and a rotatable shatt within the sleeve, one end of said shaft being formed into an expansible chuck, a nut threaded over said chuck, and an engaging member carried by said sleeve and arranged to be irought into engagement with the nut, whereby said nut may be turned and screwed upon, or unscrewed from said chuck by the rotation of said sleeve.

2. A dental hand piece including a casing, a sleeve titted within the casing, a rotatable shaft within said sleeve, one end of which is formed into a chuck, having a tapering free end, a nut threaded over said chuck and conforming in contour to the contour of the chuck, means normally locking the sleeve against movement relative to the casing, means for releasing said locking means to permit the relative lengthwise movement of the sleeve relative to the casing, means carried by said releasing -means and provided to engage with said shaft, when said sleeve is moved relative to the casing to lock said shaft against rotation, and interlocking means carried by the sleeve and nut, re spectively, vand adapted to be brought into interlocking position when the sleeve is moved relative to the casing through which the nut may be turned by rotating the sleeve relative to the shaft.

A dental hand piece including a sleeve, a shaft rotatable therein, one end of which is formed into a chuck, provided to receive a drill, a nut threaded onto said chuck and provided to contract the chuck to secure the drill therein, interlocking means carried by the sleeve, normally out of engagement with said nut and adapted to be brought into engagement with the nut, by the lengthwise movement of the sleeve on the shalt whereby said nut may be screwed onto or unscrewed from the chuck by the rotation of the sleeve.

L. A dental hand piece, including a casing having two openings theretlnough, a sleeve titted within the casing and having an oritice alined with one of said openings, and a depression alincd with the other opening, a shaft within said sleeve having a recess alined with the last mentioned opening. a yieldable member secured to said casing, a pin carried thereby and normally projecting thr ugh said alined openings in the vasing and sleeve, a yieldable member attached at one end to said pin and having its other end tree, a tulcrmn over which said last mentioned yieldable member operates, a pin carried by the free end of said last mentioned yieldable member and projecting through the opening in the casing which is alined with said recess, an cxpansible chuck into which one end oi? said shalt is termed, a nut within the sleeve threaded over said chuck and interlocking members carried by the sleeve and nut respectively, and capable of being brought into and out of engagement said first mentionedv pin being releasable from the sleeve to permit the lengthwise movement of the sleeve relative to the easing, whereby said interlocking means may be brought into engagement and whereby said last mentioned pin is free to enter said recess to lock the shaft against rotation, relative to said casin in testimony whereof I have signed my name to this specification in the presence ol two subscribing witnesses.

ROBERT E. GHAVEQ.

Witnesses IRENE BRUNS, W M. A. CATIIEY. 

